Thermochemical energy store and system comprising the thermochemical energy store

Abstract

A thermochemical energy storage, a system including the thermochemical energy storage, and uses of the thermochemical energy storage. The thermochemical energy storage includes one or more thermochemical cells each containing a container with a reaction phase and a gas phase. Providing a technically simple thermochemical energy storage with low maintenance requirements, the container of the one or more thermochemical cells each have a fluid inlet and fluid outlet connected to the primary heat medium circuit, each of which opens into the gas phase in the container.

1 - 26 . (canceled) 
     
     
         27 . A thermochemical energy storage, comprising:
 one or more thermochemical cells, each comprising a container in which, in an operating state, a reaction phase comprising at least one reactant and solvent, and a gas phase, comprising a carrier gas enriched with solvent, is formed;   a primary heat medium circuit with a heat transfer medium for removing and introducing thermal energy from the thermochemical energy storage or in the thermochemical energy storage;   a fluid circuit for diverting the carrier gas from at least one of the thermochemical cells and for introducing the carrier gas in at least one of the thermochemical cells;   at least one solvent line for introducing solvent into the reaction phase of at least one of the thermochemical cells;   whereby the reactant is selected from a group consisting of salts, hydroxides, carbonates and ionic liquids, so that when the solvent is fed into the reaction phase of at least one of the thermochemical cells, due to an exothermic reaction of the reactant with the solvent, thermal energy is released to the heat transfer medium in the primary heat medium circuit and when heat is supplied via the heat transfer medium to the reaction phase of at least one of the thermochemical cells, solvent is transferred from the reaction phase into the gas phase; and   wherein the container of the at least one thermochemical cell comprises a fluid inlet and a fluid outlet connected to the fluid circuit, which end in the gas phase in the container, respectively.   
     
     
         28 . The thermochemical energy storage according to  claim 27 , wherein the thermochemical energy storage has a condenser in the fluid circuit for condensation of solvent from the carrier gas. 
     
     
         29 . The thermochemical energy storage according to  claim 28 , wherein the thermochemical energy storage has a condensate container for storing the solvent condensed in the condenser from the carrier gas, and that the solvent line is connected to the condensate container. 
     
     
         30 . The thermochemical energy storage according to  claim 27 , wherein the fluid circuit is closed with respect to the environment and has ambient pressure. 
     
     
         31 . The thermochemical energy storage according to  claim 27 , wherein the fluid inlet has an inlet opening and the fluid outlet has an outlet opening, whereby the inlet and outlet opening are each provided in the top of the container of the at least one thermochemical cell. 
     
     
         32 . The thermochemical energy storage according to  claim 27 , wherein the fluid inlet has a first fluid guide section, the first fluid guide section being designed to deflect the carrier gas guided in the fluid circuit in the direction of the reaction phase. 
     
     
         33 . The thermochemical energy storage according to  claim 32 , wherein the first fluid guide section comprises at least one tangent in longitudinal section, which penetrates the respective thermochemical cell from its top in the direction of its bottom. 
     
     
         34 . The thermochemical energy storage according to  claim 27 , wherein a circulation fan is arranged in the fluid circuit. 
     
     
         35 . The thermochemical energy storage according to  claim 27 , wherein:
 the one or more thermochemical cells comprises at least one heat exchanger connected to the primary heat medium circuit; and   the heat exchanger is in contact with the reaction phase.   
     
     
         36 . The thermochemical energy storage according to  claim 35 , wherein one of:
 the heat exchanger is a tubular heat exchanger which is arranged within the reaction phase of the respective thermochemical cell; and   the heat exchanger is a surface heat exchanger which is arranged at least one of:
 above the bottom; and 
 on at least one side wall of the respective thermochemical cell. 
   
     
     
         37 . The thermochemical energy storage according to  claim 28 , wherein the thermochemical energy storage has a secondary heat medium circuit, via which the condenser can be connected to a low-temperature source. 
     
     
         38 . The thermochemical energy storage according to  claim 37 , wherein the condenser is configured to be connected via the secondary heat medium circuit to one or more of the thermochemical cells as a low-temperature source. 
     
     
         39 . The thermochemical energy storage according to  claim 27 , wherein a filling level sensor is provided on the container of the one or more thermochemical cells. 
     
     
         40 . The thermochemical energy storage according to  claim 27 , wherein the thermochemical energy storage has a safety tank with a leakage detector, in which the one or more thermochemical cells are accommodated. 
     
     
         41 . The thermochemical energy storage according to  claim 27 , wherein the primary heat medium circuit comprises controllable valves for connecting one or more of the thermochemical cells to a heat source or heat sink. 
     
     
         42 . The thermochemical energy storage according to  claim 27 , wherein the thermochemical energy storage has a control unit which is programmed to control the valves of at least one of the primary heat medium circuit and the secondary heat medium circuit in dependence of the state of charge of the thermochemical cells for the removal or supply of thermal energy. 
     
     
         43 . The thermochemical energy storage according to  claim 42 , wherein the control device is further programmed to at least one of:
 actuate the valves of the primary heat medium circuit for charging an uncharged or only partially charged thermochemical cell in case a predetermined threshold temperature of a heat source connected to the primary heat medium circuit is exceeded;   read out the level sensors of the thermochemical cells and, in case the fill level in a thermochemical cell falls below a predetermined fill level threshold value, to output a signal which indicates the complete charging of that thermochemical cell;   in the case of a fully charged thermochemical cell, determine the temperature spread of the heat transfer medium when charging the thermochemical cell, and, if the temperature spread falls below a predetermined temperature spread threshold value, to actuate the valves in such a way as to disconnect the fully charged thermochemical cell from the primary heat transfer medium circuit; and   upon receipt of a signal to release heat from the energy storge to a heat sink, actuate a pump in a solvent line to supply solvent from the condensate container to the reaction phase of a charged or partially charged thermochemical cell.   
     
     
         44 . A system comprising a thermochemical energy storage according to  claim 27 , comprising:
 a heat pump having a condenser for delivering energy to a heat sink and an evaporator for receiving energy from a heat source;   wherein the evaporator of the heat pump is coupled as a further heat sink to the primary heat medium circuit of the thermochemical energy storage.   
     
     
         45 . The system according to  claim 44 , wherein the heat pump comprises a heat exchanger coupled to the evaporator, which is connected to the primary heat medium circuit of the thermochemical energy storage. 
     
     
         46 . A method of using the thermochemical energy storage according to  claim 27 , comprising:
 operating the thermochemical energy storage in a building for heating or as buffer storage.